It is known to provide an optical bus between circuit boards to obtain a high-bandwidth connection between them. In one type of architecture, the boards are connected in a loop with an optical repeater on each board. In another known design, an optical bus distributes a light signal to a number of receivers by providing bent fibers that allow a portion of the light propagating along them to be transmitted out of them to light detectors. Neither of these systems provides an optimal solution for optical communication between a set of circuit modules, particularly where cost, versatility, and compliance with other bus standards are important considerations.